January 19, 2025, 7:31 am | Read time: 8 minutes

Just 20 virus particles are enough to have you hanging over the toilet. The norovirus is a tiny but quite aggressive pathogen, ranking among the most common causes of gastrointestinal infections worldwide. Children are particularly often affected by this nasty virus.^1,2,3 FITBOOK compiles all the essential information about the disease.

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What is the norovirus?

The norovirus is a highly contagious virus that leads to severe diarrhea and vomiting. More specifically, it is very adaptable, which is why one can contract a norovirus infection multiple times.⁴ The most common transmission method of noroviruses is through contact infection: Even the smallest traces of stool or vomit from infected individuals are enough to spread the virus–usually from hand to mouth. Infection is also possible through the air: Vomiting produces tiny, infectious droplets (aerosols) that linger in the air.⁵ Because it is so easily transmitted, norovirus infections often spread rapidly, especially in communal settings like schools or kindergartens, where many people are present.⁶ One in five cases of diarrhea worldwide is due to a norovirus infection. However, there is still no vaccine available.⁷

Also interesting: Which home remedies help with diarrhea

How to recognize a norovirus infection in children?

When the norovirus strikes, it happens quickly. It takes between six hours and two days before symptoms appear.⁸ Typical symptoms include:

• Sudden, severe vomiting (often projectile)
• Severe, watery diarrhea
• Abdominal cramps
• Nausea
• Fever
• Fatigue, feeling of weakness

As quickly as the virus arrives, it also disappears. Typically, symptoms subside after one to two days.

Why is the norovirus dangerous for children?

Noroviruses are particularly problematic for children because the body loses a lot of water due to constant diarrhea and frequent vomiting. This can lead to rapid dehydration, meaning the body is under-supplied with water. Dehydration occurs especially quickly in children. Additionally, the balance of water and certain minerals (known as “electrolytes” like potassium, sodium, or magnesium) in the body can be disrupted.⁹ This can lead to heart rhythm disturbances, muscle cramps, and confusion.¹⁰ Additionally, children’s immune systems are often not yet strong enough to quickly fend off an infection. Therefore, it is especially important for parents to watch for warning signs of dehydration. These include dry lips, little or no urine, sunken eyes, or noticeable lethargy. In babies, a sunken abdomen and slack skin can also indicate a lack of fluids.

What measures should parents take during a norovirus infection?

Because the norovirus is highly contagious, the first step is to protect others! This primarily means family members, school friends, and playmates, to prevent further cases. The sick child should have some time alone, without visitors. Those not involved in caregiving should keep their distance for now. For those caring for the sick child, it is important to wash and disinfect hands thoroughly after each contact. Additionally, ensure the sick child uses their own dishes, cutlery, and towel. Bed linens and towels should be changed frequently and washed in the machine at a minimum of 140 degrees Fahrenheit. All traces of diarrhea or vomit (e.g., in the toilet) must be immediately cleaned up–as these are highly contagious! If possible, other family members should use a different toilet than the sick child.

Symptoms should be closely monitored. Normally, a norovirus infection subsides after about two days. If diarrhea persists or fever rises, a pediatrician should be consulted. Children under five should be closely observed–they are particularly sensitive to illness. In babies, severe diarrhea can irritate the sensitive skin in the diaper area. Zinc-based creams can help with this.¹¹

When should you see a doctor for a norovirus infection?

A doctor’s visit is necessary if:

• Symptoms last longer than 48 hours.
• The child shows clear signs of dehydration, such as sunken eyes or little to no urine.
• Blood appears in the stool or vomit.
• The child is extremely lethargic or barely responsive.
• Fever occurs that cannot be reduced.
• The child continues to vomit severely despite fluid intake.

The doctor will then assess the child’s condition and, if necessary, initiate an infusion to restore fluid balance. In more severe cases, hospitalization may be required.¹²

How is norovirus treated in children?

Unfortunately, there is no specific cure for norovirus–the body must fight off the virus on its own. Treatment focuses on alleviating symptoms.

• Drink, drink, drink! Especially for children, fluid intake is crucial. Suitable options include water (non-carbonated), fruit or herbal teas (depending on taste preference, can be sweetened with a little glucose), heavily diluted fruit juice or black tea, and vegetable or chicken broth.¹³ There are also special electrolyte solutions (for children) available at pharmacies to help balance the loss of water and minerals. Don’t worry if the child doesn’t want to drink large amounts right away–patience is key. Drinks with carbonation or caffeine, sports drinks, and fruit juices are not suitable.
• Rest: Bed rest and generally plenty of rest help the body recover.
• Symptom management: Medications for nausea, diarrhea, or fever can be taken, but only in consultation with a doctor.

Important: Antibiotics are ineffective, as noroviruses are not bacteria but viruses. Also, up to two weeks after symptoms subside, infectious viruses can still be found in the stool.¹⁴

What preventive measures protect children from a norovirus infection?

Noroviruses typically enter our bodies through three different routes: contact infections (contact with infectious stool or vomit), contaminated objects (toys, cell phones, door handles, bathroom fixtures), or raw foods (salad, frozen berries, and seafood). Therefore, good, consistent hygiene is the best protection against the virus:

• Handwashing: Thorough handwashing with soap (not just a quick rinse with cold water) is especially important after using the bathroom, before eating, and after contact with sick individuals.¹⁵
• Food hygiene: Fruits and vegetables should always be washed thoroughly. Seafood must be sufficiently heated, as the virus is heat-sensitive.
• Avoid contact: Those who are sick should avoid contact with others for at least 48 hours after symptoms subside–even if they feel better.
• Household hygiene: Regular cleaning of frequently touched surfaces and toys.
• Proper laundry washing: Clothing and bed linens from infected individuals should be washed at high temperatures (at least 140 degrees Fahrenheit).

What to do in case of outbreaks in kindergartens or schools?

When norovirus spreads in communal facilities, quick action is required. Sick children must be sent home immediately to stop the spread. A norovirus infection is reportable, so in the event of an outbreak in a kindergarten or school, the local health department will also get involved. Infected children under six years old are not allowed to attend kindergarten or school. Generally, the facility can be visited again two days after symptoms have subsided. The exact timing is determined by the responsible health department.

Afterward, a thorough cleaning is necessary: Everything–from toys to toilets–should be thoroughly disinfected. If necessary, a specialized cleaning company can be hired.

More on the topic

Stomach and intestinal viruses, RSV… Infections That Frequently Affect Children

Dangerous for Children Causes and Symptoms of Food Poisoning

Can norovirus cause long-term effects in children?

Fortunately, a norovirus infection usually does not leave lasting damage. However, long-term effects cannot be completely ruled out. Studies show that people who have had an infection have a higher risk of certain gastrointestinal issues in the following years compared to those who have never contracted norovirus:

• The so-called gastroesophageal reflux disease (GERD), often accompanied by heartburn
• Constipation
• Nonspecific upper abdominal pain, also known as dyspepsia
• Irritable bowel syndrome

Why this happens is not yet fully understood. It could be that noroviruses impair the protective function of the stomach and intestinal lining. This could cause the immune system to become confused and suddenly attack harmless substances. However, more studies are needed to understand all of this.¹⁶

How to feed children after a norovirus infection?

In general, appetite is key! After a norovirus infection, the body needs to refuel with energy. However, it is important not to overdo it, as the gastrointestinal tract of children is often sensitive after such an illness. Instead of large meals, parents should offer their child several small portions throughout the day to avoid overwhelming the stomach. Continued hydration should also be maintained. A so-called bland diet is recommended for three to five days:

Well-tolerated:

• Pretzels and salted sticks are good for sodium balance.
• Rusks, crispbread, and rice cakes are crunchy yet gentle on the stomach.
• Cooked oatmeal is mild and soothing. It contains mucilage that helps the stomach lining regenerate.
• Mashed bananas are sweet yet gentle. They also contain a lot of potassium.
• Carrot puree or other cooked vegetables are simple but nutrient-rich.
• Cooked poultry is low in fat and easy to digest.

Not suitable:

• High-fat foods like grilled meat, sausage, or fried foods.
• Fresh whole-grain bread or warm bread, as it is hard to digest and can cause bloating.
• Legumes, as they are also hard to digest.
• Cocoa/chocolate
• Dairy products, cheese, eggs
• Sweets like cakes, cookies, ice cream, undiluted fruit juices, and soft drinks should be avoided, as the extra sugar stresses the intestines.
• This also applies to cola. The myth that cola helps persists–but it’s nonsense. The sugar further burdens the gastrointestinal tract.